A lot of people clam up when it is their turn to make a presentation, regardless of how many people are present in the room. Do not worry. This is a common reaction to many speakers and the good news is that it is easy to overcome these pesky hang-ups by avoiding the following.
Relying on filler words: People use filler words (“um,” “ah” “like,” “you know,”) when they are uncomfortable with silence or lacking confidence. To overcome this, record yourself to understand where you are using filler words and train yourself to simply pause instead of using a filler word. Pause is a gift to the listener because the listener needs time to process what you are saying.
Vocal fry: This is a sound a speaker makes in their throat when they run out of air as they speak. These mistakes often tend to distract the audience from the main topic. To overcome, take a deep breath and deliver one sentence at a time to get a sense of what it feels to have enough air in your lungs. Next, record yourself speaking to understand what the vocal fry sounds like, and practice eliminating the vocal fry through breathing.
Sounding cold or aggressive: Many speakers struggle to sound warm and friendly while still commanding authority. When people focus too much on sounding formal, assertive or smart, they can come off as cold and aggressive. Over-articulating is one of the ways people can sound excessively distant. Instead of articulating every letter, the trick is using a strong intonation on the parts of the words that have the most information, and not on the less important sounds like prefixes, conjunctions and prepositions.